<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>HTML5原⽣ 拖拽</title>
  <style>
    .main {
      display: flex;
      justify-content: space-around;
    }
  
    .left {
      width: 300px;
      height: 500px;
      margin-right: 10px;
      border: 1px solid red;
      text-align: center;
      box-sizing: border-box;
      padding: 1pxx
    }
  
    .right {
      width: 300px;
      height: 500px;
      border: 1px solid lightseagreen;
      text-align: center;
      box-sizing: border-box;
      padding: 1px;
    }
  
    .txt {
      border: 1px solid gray;
      margin: 1px;
      padding: 5px;
      cursor: move;
    }
  </style>
</head>
<body>
  <main class="main">
    <div class="left" id="left">
      <div class="txt-show">左边区域</div>
      <div id='txt1' draggable="true" class="dragable txt txt1">可移动的文字一</div>
      <div id='txt2' draggable="true" class="dragable txt txt2">可移动的文字二</div>
      <div id='txt3' draggable="true" class="dragable txt txt3">可移动的文字三</div>
      <div id='txt4' draggable="true" class="dragable txt txt4">可移动的文字四</div>
      <div id='txt5' draggable="true" class="dragable txt txt5">可移动的文字五</div>
    </div>
    <div class="right" id='right'>
      <div class="txt-show">右边区域</div>
    </div>
  </main>
  <script>
    let txtObj = document.getElementsByClassName('txt')
    for (let i = 0; i < txtObj.length; i++) {
      txtObj[i].ondragstart = handle_start
      txtObj[i].ondrag = handle_drag
      txtObj[i].ondragend = handle_end
    }

    function handle_start(e) {
      e.dataTransfer.setData('Text', e.target.id)
      console.log('handle_start-拖动开始')
    }

    function handle_drag(e) {
      console.log('handle_drag-拖动中')
    }

    function handle_end(e) {
      console.log('handle_end-拖动结束')
    }
    let target = document.getElementById('right')
    target.ondragenter = handle_enter
    target.ondragover = handle_over
    target.ondragleave = handle_leave
    target.ondrop = handle_drop

    function handle_enter(e) {
      e.preventDefault()
      console.log('handle_enter-进入目的地')
    }

    function handle_over(e) {
      e.preventDefault()
      let returnObj = e.dataTransfer.getData('Text')
      console.log(returnObj + '-handle_over-在目的地范围内')
    }

    function handle_leave(e) {
      e.preventDefault()
      let returnObj = e.dataTransfer.getData('Text')
      console.log(returnObj)
      console.log('handle_leave-没有放下就离开目的地')
    }

    function handle_drop(e) {
      e.stopPropagation(); // 不再派发事件。解决Firefox浏览器，打开新窗口的问题。
      e.preventDefault()
      let returnObj = e.dataTransfer.getData('Text')
      if (returnObj) {
        e.target.appendChild(document.getElementById(returnObj))
      }
      console.log(returnObj + '-handle_drop-在目的地区释放')
    }
  </script>
</body>
</html>